1. Field of the Invention
This invention relates, generally, to solar collectors. More particularly, it relates to solar collector housings that are easily opened and closed without tools. It also relates to solar collectors having polymer absorbers that expand and contract as temperatures rise and fall without placing stress on absorber tubes.
2. Description of the Prior Art
Conventional solar collectors include a cover and a base that are secured to one another by conventional fastening means including screws, nuts, rivets and the like. These fasteners perform well but require the use of tools. Opening and closing such housings cannot be accomplished quickly due to the large numbers of fastening members.
Thus there is a need for a solar collector housing that can be opened and closed quickly without the use of tools.
Unlike conventional metallic absorbers, polymer absorbers used in some solar collectors are subject to significant length changes due to thermal expansion and contraction. Over the course of a sunny day the absorber may experience temperature swings that may exceed 150° F., resulting in a change in length that may exceed an inch.
Prior art solar collectors mount both ends of the metallic absorber in a fixed position. The greater temperature-responsive expansion and contraction that polymer absorbers experience puts stress on the absorber tubes and eventually causes a leak or total failure. The art of solar collectors has long accepted this problem as being an inherent weakness of polymer absorbers and has responded to the problem by somehow allowing for the length change of polymer absorbers and the absorber tubes as needed.
Thus there is a need for an improved mounting means for a polymer absorber. The improved mounting means would accommodate the temperature-related expansion and contraction of a polymer absorber but would not make polymer absorber installation more difficult.
However, in view of the prior art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the art that the use of conventional, tool-requiring fastening members to secure the cover to the base was unacceptable. Nor was it obvious that a better mounting means for the polymer absorber was needed. It follows that the solution to both unperceived problems was not obvious.